Portable photographic contact printer



P. A. SHERIDAN PORTABLE PHOE'OGR APHIC CONTACT PRIRZER Aug. 11, 1942.

Filed Jan. 2, 1941 Patented Aug; 11, 1942 PORTABLE PHOTOGRAPHIC CONTACT PRIN TER

Phil A. Sheridan, Bethesda, Md.

Application January 2, 1941, Serial No. 372,918

Claims.

This invention relates to photographic apparatus and more particularly to a readily portable mechanism for making contact prints.

One of the objects of the present invention is to provide a light-weight, portable apparatus for making photographic contact prints, the construction being especially useful for securing reproductions of letters, writings, drawings, etc., and avoiding the necessity of utilizing complicated and costly photostatic machinery.

Another object is to provide a device of the foregoing character which is so constituted that contact prints of excellent quality may be secured without the exercise of any special knowledge or skill on the part of the operator.

Yet another object is to provide a relatively small apparatus of the above type which is so constituted as to be capable of obtaining contact prints of work-pieces having a length great- 1y exceeding one of the dimensions of the apparatus.

A further object resides in the general construction and arrangement of the various parts constituting the novel device whereby a contact printer of unusual simplicity is achieved and one which may be manufactured at a relatively low cost.

Other objects and novel features of the invention will appear more fully hereinafter from the following detailed description when taken in connection with the accompanying drawing illustrating one form of the invention. It is to be expressly understood, however, that the drawing is employed for purposes of illustration only and is not designed as a definition of the limits of the invention, reference being had for this purpose to the appended claims.

Referring to the drawing, wherein similar reference characters refer to like parts throughout the several views:

Fig. 1 is a perspective view of the contact printing apparatus constituting the present invention and illustrating the device in use;

Fig. 2 is a longitudinal sectional view taken along lines 2-2 of Fig. 1;

Fig. 3 is a bottom view of the housing of Fig. 2, and.

Fig. 4 is a transverse sectional view taken on lines 44 of Fig. 2.

Referring more particularly to Figs, 1 and 2, a photographic apparatus embodying the principles of the present invention is illustrated therein as including a work positioning and holding device 5 withwhich a novel rolling light box 6 cooperates during operation of the construction.

The device 5 is constituted by a plurality of transparent sheets between which a work-piece 8, such as a letter to be reproduced, and a sheet I of sensitized paper are placed in contacting superposed relation. Preferably, the device 5 includes three sheets 9, l0 and II of relatively thin flexible, plastic material, the top and bottom sheets 9 and l I being clear and transparent while the intermediate sheet may be yellow in order to perform the function of a yellow filter in the event colors are included in the work-piece to be reproduced. The use of flexible plastic material for the device 5 enables the assembly of superposed sheets 9, l0 and H to be readily rolled up to form a package in order that it may be readily transported, with the light box 6, from place to place. Moreover, the flexibility of the sheets enables maximum areaof contact between the work-piece 8 and the printing paper I, as the light box 6 is rolled back and forth over the device 5, thus securing prints of unusual clarity. This latter feature will be referred to more fully hereinafter.

As illustrated, the light box 6 is formed from a single piece of metal which is bent in such a manner as to provide a housing having a top Wall l2, side walls l3 and I4 and an open bottom l5. A tubular light source or lamp i6 is positioned within the light box 6 and is arranged to be supplied with electrical energy from a con- I venient outlet as by conductors H and i8. In order to support the lamp, a pair of combined support and terminal blocks l9 and 20 are sccured at opposite ends of the top I2 as by screws 2! and 22. The lamp [6 is provided at either end with electrodes 23 and 24, and, when these are inserted within suitable sockets in the terminal blocks l9 and 20, the lamp is supported by the top l2 and may be supplied with electrical energy by the manipulation of a switch 25 conveniently arranged at the top of the box and placed in series with one of the conductors H or IE.

Means are provided by the present invention for enabling the light box 6 to be rolled back and forth over the device 5 in order to properly expose the sensitized paper and to secure and maintain firm frictional contact between the latter and the Work. To this end, a pair of cylindrical rollers 26 and 21 are rotatably mounted, as by means 'of axles 28 and 29 in end straps 30 and 3!, the latter being suitably secured to the side walls [3 and I4. Preferably, the end straps 30 and 3| do not completely close the open ends of the box 6, openings 32 and 33 providing suitable ventilation for the interior of the box when the lamp is in use.

As illustrated more particularly in Fig. 4, the rolllers 2B and 21 are arranged closely adjacent the side walls I! and M respectively. It will also be observed that the aforesaid rollers extend a slight distance only below the lower edges of the side walls and the end straps. By using this construction, loss of light from the interior of the box is prevented and clear, sharp prints are obtained. The above extension of the rollers beyond the plane of the bottom of the box need only be sufficient toenable a slight clearance between the box and the top sheet of the device 5 in order to avoid contact between the said sheet and box.

In operation, and assuming that the operator desires to make the usual negative of a black and white writing. drawing or print, the various sheets, work-piece and printing paper are arranged as shown in Figs. 1, 2 and 4, with the workpiece 8 and sensitized paper 1 between the uppermost, clear transparent sheet 9 and the intermediate yellow sheet l0. After turning on the switch 25 and effecting energization of the lamp IS, the operator grasps the light box 6, as illustrated in Fig. 1, and, while exerting a'downward pressure thereon, moves the box back and forth over the work-piece 8 and printing paper 1 a sufficient number of times, at a uniform speed, to obtain a proper exposure. The print is thereafter subjected to the action of the developing, washing and fixing baths in the well known manner, to obtain the finished negative print. It is desired to particularly emphasize that, during the above operation, the area of the printing paper, subjected at any instant to the light confined within the box, is pressed into firm contact with the work-piece. Thus, due to the construction provided, and the rolling action of the apparatus, clear and exact prints will be secured. All imperfect printing, distortion and ibgging, due to lack of contact between the printing paper and work-piece at spaced intervals. is avoided by the arrangement proposed.

During the rolling of the light box back and forth over the work-piece as above described, the latter and the sensitized paper with which it contacts are tightly and frictionally maintained in contacting relationship by the pressure exerted by the operator and the nature of the surface of the flexible plastic sheets 9 and I0. Morover, during operation, it has been found that the rolling action of the light box generates a certain amount of static electricity which aids in preventing any displacement of the work with respect to the printing paper during exposure.

In the event it is desired to use a yellow filter in making a print, the work-piece and sensitized paper are placed between the yellow flexible sheet l0 and the bottom sheet ll prior to exposure in accordance with the above described process.

It will be understood that, in Figs. 2 and 4, the thickness of the sheets I, 8, 9, l0 and II has been materially increased for purposes of illustration. In practice, sheets 9 and I0 would be in firm frictional engagement throughout their areas, except for the area occupied by the work I and-printing paper 8.

There is thus provided a novel, portable contact printing apparatus which is unusually simple in construction and which may be used without anyspecial training or experience to secure clear and exact reproductions of writings, drawings, designs, etc. In addition to the desirable features already pointed out, it will be readily appreciated that the presentinvention includes the great advantage of making contact prints of work-pieces having an area which greatly exceeds the area of the light box, it being only necessary that the latter have a length equal to the smaller dimension of the work-piece' In the foregoing description, wherein the work-piece is placed on top of the sensitized paper, it will be understood that a direct reading negative print is obtained. If it is-desired to secure the usual reflex negative, the work-piece and printing paper are placed between flexible sheets Ill and H to obtain the benefit of the yellow filter effect of sheet It), the sensitized sheet being on top of the work-piece.

While only one embodiment of the invention has been illustrated and described herein, it will be understood that the same is not limited thereto but may be embodied in various forms, as understood by those skilled in the art, without departing from the spirit of the invention. Reference will, therefore, be had to the appended claims for a definition of the limits of the invention.

What is claimed is:

l. A. rolling contact printing device comprising a pair of superposed sheets of flexible transparent plastic material between which a work-piece to be copied and a sensitized sheet are arranged, and means for exposing said sensitized sheet and for pressing all of said sheets and work-piece into firm frictional engagement with each other comprising an elongated, rectangular housing having top. side and end walls, the bottom being open, an elongated light source carried by said housing for emitting substantially'equal light intensity throughout the length of the housing. and a pair of rollers rotatably mounted in said end walls and arranged closely adjacent the side walls and extending but slightly below the lower edges of the side walls to prevent loss of light from the housing and prevent contact between said edges and the uppermost flexible sheet as the operator rolls said housing back and forth over said superposed sheets.

2. A rolling contact printing device comprising a pair of superposed sheets of flexible transparent plastic material between which a work-piece to be copied and a sensitized sheet are arranged, and means for exposing said sensitized sheetand for pressing all of said sheets and work-piece into firm frictional engagement with each other comprising an elongated, rectangular housing having top, side and end walls, the bottom being open,

a light source carried by said housing and positioned within the upper portion thereof, said source being substantially coextensive with the length of the housing for securing equal light intensity from one end of the housing to the other, and a pair of rollers rotatably carried by said end walls and positioned closely adjacent the side walls whereby the housing may be rolled back and forth across the assembled sheets and surface to expose the sensitized sheet and press said sheets in firm frictional engagement,

3. A rolling contact printing device comprising a substantially rectangular, elongated casing having top, side and end walls, the bottom being open, and a light source carried by said housing and positioned within the upper portion thereof, said source being substantially coextensive with the length of the housing for securing equal light intensity from one end of the housing to the other, and a pair of rollers rotatably carried by saidend walls and positioned within the housing, said rollers being spaced apart and located closely adjacent the side walls and extending a slight distance only below the lower edges of the latter.

4. A rolling contact printing device comprising a substantially rectangular, elongated casing having a top and a pair of side walls formed from a single sheet of metal, the bottom and ends of the housing being open, a light source supported from said top within the housing, said source extending substantially throughout the length of the housing, a pair of cylindrical rollers within the housing and positioned closely adjacent opposite side walls thereof, said rollers being coextensive with the length of each side wall, and means for rotatably supporting said rollers comprising a metal strap partially closing the bottom portions of each of the open ends of the housing, the lower edges of said straps and side walls being arranged in coplanar relation and the rollers extending but slightly below said edges.

5. A rolling contact printing device comprising a pair of superposed sheets of flexible transparent plastic material between which a work-piece to be copied and a sensitized sheet are arranged, and means for exposing said sensitized sheet and for pressing all of said sheets and work-piece into firm frictional engagement with each other comprising an elongated, rectangular housing having top, side and end walls, the bottom being open an elongated light source within the housing and extending substantially throughout the length thereof for emitting substantially equal light in tensity throughout the length of the housing, means for supporting the ends of said source Irom the top of the housing including a pair or terminal blocks, one secured to each of the opposite ends of said top, and a pair of equal-dianr etered rollers within the housing rotatably supported at their respective opposite ends by the ends of said housing and extending from one end of the housing to the other, each roller being arranged closely adjacent a side wall of the housing and extending but slightly below said side wall andthe housing end walls to prevent loss of light from the interior of the housing and prevent contact between the lower edges of the housing and the uppermost flexible sheet as the housing is rolled back and forth over said superposed sheets.

PHIL A. SHERIDAN. 

